Video services, such as broadcast television and video on demand services, are frequently provided to viewers over a shared medium, such as a hybrid fiber coaxial network. A headend device coupled to the shared medium provides programs in response to viewer requests generated by a user device, such as a set top box, that is similarly coupled to the shared medium. The user device receives the requested program from the headend over the shared medium and provides the program for display to the viewer. Service providers are increasingly adding non-video services, such as telephone services, audio services, and high speed data access services, over the same shared medium used to deliver video services. Because of the finite bandwidth of the shared medium and the large number of users using the shared medium, during peak usage times the shared medium may become loaded to capacity, preventing the headend from fulfilling a requested service to one or more users. The inability to provide a requested service over the shared medium may lead to user dissatisfaction, and may inhibit the service provider from generating additional revenue when the requested service requires payment of an additional fee, such as a video on demand request.
Until relatively recently a headend provided all broadcast television channels over the shared medium irrespective of whether each of the television channels had viewers. Consequently, valuable bandwidth of the shared medium might be consumed by one or more channels that have no viewers. With the advent of newer technologies, such as switched digital video, a headend can selectively provide channels over the shared medium depending on whether there are viewers of the respective channels. Channels that have no viewers will not be provided over the shared medium, and consequently will not consume bandwidth of the shared medium. This ability to selectively provide broadcast programming on an as-requested basis frees bandwidth of the shared medium for other services.
When a viewer requests a channel change in a switched digital video system, a channel change request is generated by the user device and is communicated from the user device to the headend, which determines whether or not the requested channel is already being provided over the shared medium. If so, the headend can merely provide the frequency of the requested channel to the user device, which can then tune to that frequency to obtain the requested channel. If the requested channel is not currently being provided over the shared medium, the headend will ensure sufficient bandwidth exists on the shared medium and, if so, will determine an appropriate frequency on which to provide the requested channel, begin streaming the requested channel over the shared medium, and provide the frequency to the user device. While any viewer may randomly change the channel during a program in a relatively unpredictable manner, it is especially common for viewers to change channels, referred to herein as channel surfing, during the display of advertisements. Consequently, when a popular program with a high viewership begins an advertising break, a switched digital video system may be required to rapidly provide a relatively high number of new channels over the shared medium in a relatively short period of time to satisfy the channel change requests of the viewers, which can quickly consume the bandwidth of the shared medium. As the bandwidth of the shared medium reaches capacity, video on demand requests may not be able to be fulfilled, and bandwidth allocated to data services may be reduced, slowing down Internet access and data downloads.
Channel surfing behavior follows certain patterns based on viewer habits, program content, and many other factors. Certain viewers are habitual channel surfers and move from channel to channel at the first instance of an advertising break. Other viewers channel surf based on an interest level of the program they were viewing immediately prior to the advertising break. Viewers may be less likely to channel surf from a high interest program for fear of missing a portion of the program should they not return to the program prior to the end of the advertising break, but the same viewers may not hesitate to channel surf from a low interest program because they hope not to return to the original program if they can find other programming that interests them more. Moreover, the effect of channel surfing on the shared medium differs based on whether the destination channel is already being provided over the shared medium or whether the destination channel must be provided in response to the request, which requires allocation of additional bandwidth. Because viewers are more likely to channel surf during an advertising break, it would be advantageous if a service provider could allocate advertisements among channels based on surfing behavior of the viewers in a manner that would minimize channel surfing during advertising breaks.